A wide variety of mounting assemblies and brackets have been developed for supporting an electrical fixture such as lights and ceiling fans. The mounting assemblies are required to be fastened securely to the structural support of the ceiling to properly support the weight of the electrical fixture. Electrical fixtures, such as ceiling fans, can be mounted directly to an electrical box provided the electrical box is rated for ceiling fans and is securely mounted to a structural member.
Typically a cross bar is attached between the adjacent ceiling joists by nails, screws or other fasteners. A ceiling fan rated electrical box is then attached to the cross bar and the electrical fixture is attached to the electrical box. The electrical box is required to be made of heavy gauge materials and be rated for supporting the weight of the electrical fixture. Many mounting systems have an expandable bar that can be used to retrofit an opening in the ceiling. The existing electrical box is removed and the bar is inserted through the opening in the ceiling. The bar is then expanded to engage the opposing surfaces of the ceiling joists. The electrical box must then be installed through the opening in the ceiling on the cross bar so that the bottom end of the electrical box is flush with the outer face of the ceiling. While these devices are generally effective, they can be cumbersome and difficult to mount correctly without damaging the existing ceiling.
Various devices have been proposed for mounting a support over the existing ceiling by screws or bolts that extend through the ceiling material and into the ceiling joist or support. One example is disclosed in U.S. Pat. No. 5,183,233 to LaPalomento which discloses a universal ceiling support. The assembly includes a support panel that is affixed to the grid work of a ceiling by screws that extend through the ceiling tile and into the grid work. The panel has a hole to enable wires to pass through to the ceiling fan or fixture. The panel has a slot in the rear to hold the panel flush against the flat surface while carrying the wires in the slot. A bracket is attached to the panel for supporting the weight of the fixture. The bracket is mounted to the panel over the slot and includes a hole to allow the wires to pass through.
Another mounting device is disclosed in U.S. Pat. No. 5,522,577 to Roesch. This patent discloses a ceiling pan support arrangement for attaching to a beam located inwardly from the support beam and the surface of the ceiling. The device includes a box with a bottom wall attached to the beam, side walls and a flange extending outwardly from the side walls. A rigid metal plate is positioned over the open end of the box and fasteners are passed through openings in the plate and the flange of the electrical box and into the beam. This arrangement is generally suitable only where a cross beam in available or can be conveniently installed.
Another example of a mounting system is disclosed in U.S. Pat. No. 5,939,671 to Gretz. This device includes a box with a bottom wall that is formed in a series of steps so that one of the steps can be attached to the ceiling support. A cover plate can be attached to the box to cover the opening.
Still another mounting device is disclosed in U.S. Pat. No. 6,152,413 to Gretz. This device includes a mounting block having a central electrical box with a closed bottom, an open top and a planar medallion portion about the periphery of the of the box. The box has a centrally located mounting hole and pair of slots providing adjustable channels.
An example of an electrical box that is constructed to support a ceiling fan or other electrical fixture is disclosed in U.S. Pat. No. 6,100,469 to Jorgensen et al. The electrical box has a top portion and a side portion extending around the top portion. The side portions have two opposing spaced tabs extending inwardly toward each other. The tabs have an opening therein. At least one mounting hole is formed in either the top portion, side portion or the corner formed between the top and side portion. A mounting screw is inserted through the mounting holes to engage the ceiling joist and to support the electrical box.
While the prior devices have generally been suitable for the intended use, many of these devices can not be used to retrofit an existing structure. Accordingly, there exists a need in the industry for improved mounting systems for electrical fixtures.